Alkylguanylisoureas



United States PatentO ALKYLGUANYLISOUREAS Ingenuin Hechenbleikner,Stamford, Conn., assiguor to American Cyanamid Company, New York, N. Y.,a corporation of Maine No Drawing. Application April 5, 1954, Serial No.421,167

7 Claims. (Cl. 260-564) The present invention relates to new and usefulalkylguanyhsourea compounds which are capable of represenmoon by thegeneric formula R\ NH -R R The above compounds may also be prepared bytreating the tetraalkylguauylchloroformamidine hydrochloride with onemolar equivalent of an alkali metal alkoxide to produce thehydrochloride salt of the alkylguanylisourea,

and thereafter forming the free base by adding one molar equivalent ofan alkali metal hydroxide or alkoxide.

Methods of preparing the tetraalkylguanylchloroformamidinehydrochlorides employed in the present process are disclosed in mycopending application, Serial No. 35 8,- 549, filed May 29, 1953. Forexample, tetraethylguanylchloroformamidine hydrochloride is formed byreacting diethylcyanamide with hydrogen chloride at a temperature withinthe range of from 60 to 150 C. The reaction may be illustrated asfollows:

CsHs

-H C l Call: 02H! Ninety grams of hydrogen chloride was passed into 196g. of diethylcyanamide during a period of one hour. The diethylcyanamidewas stirred rapidly during the addition of the hydrogen chloride gas,and the temperature rose gradually to 85 C. The mixture was then heatedfor thirty minutes and the temperature was maintained at about 150 C.The product (l,l,3,3-tetraethylguanylchloroformamidine hydrochloride)was a colorless crystalline solid which melted at 35-40 C.

In the present process the alkali metal alkoxide is formed by dissolvingthe alkali metal in the alcohol. The reaction of thetetraalkylguanylchloroformamidine hydrochloride with the alkali metalalkoxide is carried out in an inert organic solvent at room temperatureor slightly above and usually at a temperature within the range of fromabout 20 C. to C. Compounds which may be employed as solvents in theprocess are benzene, toluene, acetonitrile, tetrahydrofurane, dioxane,and the lower aliphatic monohydric alcohols such as the methyl, ethyl,propyl, and butyl alcohols.

2,704,297 Patented Mar. 15, 1955 The invention is further illustrated,but not limited, by the following examples:

EXAMPLE 1 1,1,3,3-tetramethyl-O-methylguanylisourea OH; NH o-cH. CH:

23 g. (1.0 mol) of sodium was dissolved in 400 cc. of methyl alcohol.213 g. (1.0 mol) of tetramethylguanylchloroformamidine hydrochloride wasadded slowly with stirring to the methyl alcohol solution maintained at40 C. After standing at room temperature for one hour, the reactionmixture was filtered and the filtrate was evaporated to dryness atreduced pressure. 200 g. of thel,1,3,3-tetramethyl-O-methylguanylisourea hydrochloride was obtainedwhich melted at C. with decomposition. The free base was formed byneutralizing the hydrochloride salt with one mol equivalent of sodiumhydroxide.

EXAMPLE 2 1,1,3,3-tetramethyl-O-ethylguanylisourea CH3 NH O-CrHs CH1 CCH3 213 g. (1.0 mol) of tetramethylguanylchloroformamidine hydrochloridewas added slowly with stirring to a solution of 46 g. (2.0 mols) ofsodium in 400 cc. of ethyl alcohol maintained at 4050 C. Theprecipitated sodium chloride was filtered ofi and the filtrate washeated under vacuum to remove the alcohol. The residual product g.) wasa colorless oily liquid. Titration in alcohol with 0.5 N HCl gave aneutralization equivalent of 188 (calcd., 187).

EXAMPLE 3 1,1 ,3,3-tetraethyl-O-isopropylguanylisourea (EH5 NHO-C:4H1C2H5 N N= --N 39 g. (1.0 mol) of potassium was dissolved in 500cc. of isopropyl alcohol. 134.5 g. (0.5 mol) of tetraethylguanylchloroformamidine hydrochloride was added slowly with stirring tothe alcohol solution maintained at 25 -30 C. The reaction mixture wasthen added to 3 liters of water. The oily product was decanted from theaqueous layer and washed with another liter of water. 214 g. of thecoloress oily liquid was obtained. Titration in alcohol with 0.5 N HClgave a neutralization equivalent of 229 (calcd., 223).

EXAMPLE 4 1,1,3,3-tetraisobutyl-O-dodecylguanylisourea C4Ho NH O-CltHzsC4H| C 419 0 KB 90 g. (0.2 mol) of tetraisobutylguanylchloroformamidinehydrochloride was added slowly with stirring to a solution of 7.8 g.(0.2 mol) of potassium in 37.2 g. (0.2 mol) of dodecyl alcohol and 400cc. of benzene maintained at 40 C. for one hour. The reaction mixturewas washed with 500 .cc. of water containing 8 g. (0.2 mol) of sodiumhydroxide.- The organic layer was heated under vacuum to remove thebenzene. The residual product (102 g.) wasa colorless oily liquid havinga neutralization equivalent of 511 (calcd., 505).

EXAMPLE 5 1,1,3,3-tetra-n-0ctyl-O-n-octylguanylisourea 60.6 g. (0.1 mol)of tetra-n-octylguanylchloroformamidine hydrochloride was added slowlywith stirring to a solution of 2.3 g. (0.1 mol) of sodium in 13 g. (0.1mol) of n-octyl alcohol and 200 cc. of dioxane maintained at 30 C. forone hour. The reaction mixture was washed with 500 cc. of watercontaining 4 g. (0.1 mol) of sodium hydroxide. The oily product wasdecanted from the aqueous layer and dried at room temperature. 64 g. ofthe colorless oily liquid was obtained. Titration in alcohol with 0.5 NHCl gave a neutralization equivalent of 680 (calc'd., 674).

EXAMPLE 6 1,1,3,3-tetradodecyl-O-octadecylguanylisourea CnHu NH -0111!"CizHu 83 g. (0.1 mol) of tetradodecylguanylchloroformamidinehydrochloride was added slowly with stirring to a solution of 3.9 g.(0.1 mol) of potassium in 25.4 g. (0.12 mol) of octadecyl alcohol and300 cc. of dioxane maintained at 35 C. for one-half hour. The reactionmixture was washed with 500 cc. of water containing 4 g. (0.1 mol) ofsodium hydroxide. The oily product was decanted from the aqueous layerand dried at room temperature. 101 g. of the colorless oily liquid wasobtained. The neutralization equivalent was 1010 (calcd., 1003).

EXAMPLE 7 1,1,3,3-tetraoctadecyl-O-n-butylguanylisourea CuHn NH O-CHOOilr! OuHn 011311 121.4 g. (0.1 mol) oftetraoctadecylguanylchloroformamidine hydrochloride was added slowlywith stirring to a solution of 4.6 g. (0.2 mol) of sodium in 150 cc. ofn-butyl alcohol maintained at 45 C. The reaction mixture was washed withone liter of water and then heated under vacuum (100 C./l mm.). Theresidual product (120 g.) was a colorless oily liquid having aneutralization equivalent of 1220 (calcd., 1217).

The alkylguanylisourea compounds of the present invention possess goodantioxidant properties and are useful as oxidation inhibitors formineral lubricating oils of the type used in internal combustionengines. The quantity of the oxidation inhibitor to be used in thelubricatanoqao-r ing oil may vary from very small proportions on the'order of 0.1% to relatively large quantities up to 5% or greaterdepending on the grade of mineral oil employed.

While the invention has been described with particular reference tospecific embodiments, it is to be understood that it is not to belimited thereto but is to be construed blroadly and restricted solely bythe scope of the appended c arms.

I claim: 1. An alkylguanylisourea of the formula R\ NH 0-12 R N ll N= NSGMLNN R NH 0R' R N ll N= N wherein R and R are members of the groupconsisting of alkyl radicals having from one to eighteen carbon atoms,

which comprises reacting one molar equivalent of atetraalkylguanylchloroformamidine hydrochloride of the formul NH 01 R N--N;d-1-/ .1101 R R 7 in which R has the above meaning, with two molarequivalents of an alkali metal alkoxide of the formula MOR' in which Mstands for an alkali metal and R has the above meaning, in an inertorganic solvent at a tempera? ture within the range of from about 20 C.to 50 C., and recovering the thus-formed alkylguanylisourea from thereaction mixture.

No references cited.

7. A METHOD OF PREPARING AN ALKYLGUANYLIXOUREA OF THE FORMULA